body {
    margin: 0;
    background-color: #000;
}
.wrapper {
    width: 1000px;
    margin: 0 auto;
}
.product {
    width: 1000px;
    display: flex;
}
.product .product-left {
    width: 450px;
    height: 600px;
    /* background-color: #cccccc; */
    text-align: center;
}
.product .product-right {
    width: 542px;
    height: 600px;
    /* background-color: #f0f0f0; */
}

/* 小盒子 */
.small-box {
    width: 450px;
    height: 450px;
    position: relative;
    border: 1px solid #ccc;
}
.small-box img {
    display: block;
    width: 450px;
    height: 450px;
}
/* 遮罩层 */
.small-box .mask {
    width: 300px;
    height: 300px;
    background-color: rgba(255,255,0,.5);
    position: absolute;
    top: 0;
    left: 0;
    cursor: move;
    display: none;
}

/* 大盒子 */
.big-box {
    width: 540px;
    height: 540px;
    border: 1px solid #ccc;
    overflow: hidden;
    position: relative;
    display: none;
}
/* 大图片 */
.big-box img {
    display: block;
    width: 800px;
    height: 800px;
    position: absolute;
    left: 0px;
    top: 0px;
}